Typically, while performing conduction state inspection or operating characteristics inspection of a target for inspection such as a semiconductor integrated circuit or a liquid crystal panel, a contact structure unit is used that includes a plurality of contact-carrying members for establishing electrical connection between the target for inspection and a signal processing device which outputs signals for inspection. In such a contact structure unit, with the recent progress in achieving a high degree of integration and downsizing of semiconductor integrated circuits and liquid crystal panels, there has been advancement in the technology by which the pitch of contact-carrying members is narrowed so as to be able to deal with a target for inspection having a high degree of integration and downsizing.
Exemplary techniques for performing conduction state inspection or operating characteristics inspection of a target for inspection, such as a semiconductor integrated circuit or a liquid crystal panel, include the four-terminal measurement technique. As far as the four-terminal measurement technique is concerned, a method is disclosed for manufacturing a contact structure unit in which a pair of contact-carrying members (contact probes), which form a contact structure held on a guide plate, have the leading ends thereof making contact with a target for contact (a measurement object) with the aim of measuring the electrical characteristics (for example, see Patent Literature 1).
Regarding the pair of contact-carrying members disclosed in Patent Literature 1, one end of each contact-carrying members makes contact with a lead and the other end makes contact with the target for contact. Herein, since the contact-carrying members in a single pair simultaneously make contact with the target for contact, four-terminal measurement is performed. According to Patent Literature 1, if the contact-carrying members in a single pair have different diameters in a direction perpendicular to the direction of inserting them in the guide plate, then the contact-carrying members can be arranged in an efficient manner.